hey guys im having some serious issues with 03 cts....two days ago i started up my car and the check engine light came on along with the traction control light and the radio displayed engine power reduced, thinking it was a mistake i briefly turned off the engine and started it again and the problem magically disappeared....unfortunately the car suddendly stalled on me on the highway, i turned the key and got it to start again but this time the engine light/traction control light along with the engine power reduced poped up again and the car wouldnt go no more then 2mph (literally 2mph). i got it towed home and yesterday morning it started up fine other then the check engine light staying on so i drove it around the block and everything "seemed" arlrite, today however im having the same problem....

this is a 2003 cts basic model, mileage is at 130k and change, and best of all my warranty is up....the car is well maintained/serviced. money is defenitely an issue so before i take it to a mechanic and get my pockets raped i wanna ask u guys for any suggestions/comments or if anyone has the same problem or better yet an actual solution for this problem.....in other words SOMEONE PLEASE HELP ME!!!!! (seriously)

 

Your going to have to get someone to read the codes in the ecm. I remember several wireing issues that could cause the problem. Check the connector at the throttle body and the connector on the drivers side rear of engine. Good Luck

 

Thanx for the reply,
I actually stop by a mechanic yesterday and there were no codes, he then said something about going into "generic mode" and found a couple of codes all related to the throttle like you mentioned, he also said that it might have something to do with "ground wires"

The funny thing is the car has been running perfectly fine for a week now.

 

Do you smell any burning oil? same happened on my CTS, turned out it need valve covers replaced.

 

So its been almost exactly 2 months since I had this problem, and unfortunately today it happened again....once again on the highway [:@]. Im not sure where to go from here, I guess my only choice now is the $dealership$ let me know what you guys think

p.s. Robo there was no burning oil smell, it must have been something else!

 

Quick update: I took her to the shop this past monday, my guy checked out all the wires and got rid of all the codes the car is running fine but he warned me that it WILL breakdown again. He said that i would have to change the throttle (something related to it) and the sensors/receivers for the accelaration pedal, that should cost me about $650.....I'm definitely looking for a second opinion!

 

Any chance this is happening while its raining? This is a common issue with C5 Corvettes - did it with mine. Not sure if it is a problem that translates to other GM models or not. My yissue was that the previous battery had leaked onto one the computers (can't remember which one off hand) and anytime it rained it cause expose portions of the wiring harness to send all kinds of funky codes (you can easily read the codes in a Vette). It finally starting causing my car engine to misfire! Made the mistake of going to the dealer twice with them being unable to figure it out, and then finally once the wiring harness was replaced the car never had an issue again.

 

I have had the exact same problem with the reduced engine power. I have a 2003 cts with 67,000 miles. I too was stranded on the high way, and could only reach about 10 mph. . I took mine to the shop and they cleaned out my throttle body, said it was a mess, and it has worked perfect since.

 

I am having the same problem as all of you. It looks like the stealership even replaced the wire harness on my throttlebody at one point to try and fix the problem, but it obviously didn't. The only difference I seem to be experiencing is that my problem seems to be preceeded by the transmission downshifting very hard. Shortly after the trans downshifts hard, I will get the "Engine Power Reduced" message and the car won't go over a few mph. Each time I experience this problem, I play with the harness on the throttle body and restart the car and the problem seems to go away. I don't know if it is because I am playing with the wire harness or just because I restarted the car. I have tried playing with the wire harness while the car is running but this doesn't trigger the "Engine Power Reduced" message, so I have a hard time believing there is a short. Anyone have any suggestions? This is getting rediculous.

 

You will need scanner to monitor throttle control data while playing with harness and see what's changing or dropping out. Also will help when car messes up you can see whats missing. You need Factory service manual (www.helminc.com) or Alldata to interpet data.